Biodiversity Loss and Its Consequences

[Audio] Evs1232: Conservation Biology And Bio extinction Lecture 2 Academic Year: 2025 / 2026 Biodiversity Loss and Its Consequences Understanding Extinction Rates, Causes, and Ecosystem Impacts Pr Fehmi Abdelmajeed boufahja.

[Audio] Course Overview The Extinction Crisis Causes of Extinction Global and Saudi Arabian extinction rates, statistics, and the scale of biodiversity loss Analyzing the five major drivers of biodiversity loss and their mechanisms Vulnerability & Consequences Environmental Change & the Future Gene pool erosion, ecosystem services loss, and impacts on human livelihoods Understanding extinction vulnerability factors and ecological cascading effects.

[Audio] Module 01 The Extinction Crisis Understanding extinction rates on global and regional scales.

[Audio] The Sixth Mass Extinction Global Biodiversity Crisis We are witnessing the sixth mass extinction in Earth's history — the first one caused entirely by human activities. Species extinctions are now 100-1000 times higher than the natural baseline. 69% 1M 18% Wildlife Decline Species Threatened Vertebrates at Risk Most Affected Regions 94% Latin America & Caribbean 66% Africa Average wildlife populations declined by 69% between 1970-2018. Many species face extinction within decades. 55% Asia Pacific.

[Audio] Species at Risk in Saudi Arabia Regional Biodiversity Challenges Endemic Species Status Total Extinct Endangered Vulnerable Near Threatened Of 21 endemic species, only 1 is listed as 'Least Concern' . None are stable or increasing, highlighting an urgent need for conservation action. Regionally Extinct Conservation Success Arabian Leopard <50 One of the world's rarest big cats, facing extinction from habitat loss and poaching in western mountains. Wild Individuals Asiatic Wild Ass Adults Remaining Arabian Oryx: Once extinct in the wild, successfully reintroduced through captive breeding Cheetah Lion.

Illegal Hunting: A Historic and Ongoing Threat Species Affected & Status Arabian Oryx (Extirpated, 1970s) Sand Gazelle (Endangered) Nubian Ibex (Endangered) Houbara Bustard (Endangered) Key Drivers & Enablers • Demand for Meat, Trophies, Traditional Medicine Improved Vehicle Access Sustains Black- Market Supply Chains Department of Environmental Sciences Academic Year 2024-2025 Ecological Consequences Unsustainable Off-take Thresholds Exceeded Erosion of Genetic Diversity.

Conservation in Action: Taif & A1-Ula Centres Implementing Science-Based Strategies Molecular Pedigree Management Minimizing Inbreeding Arabian Leopard Arabian Oryx Post-Release Monitoring Quantifies Survival Rates Tracks Home-Range Establishment Assesses Gene Flow Advanced genetic analysis ensures diversity in captive populations. Success Metrics: Oryx down-listed from Extinct to Vulnerable First wild-born leopard cubs documented, validating soft-release and prey- base enrichment Department of Environmental Sciences I Academic Year 2024-2025.

Key Conservation Challenges: Invasive Species & Disease Management Module 4: Threats and Mitigation Strategies Invasive Species Competition Mesquite Native Riparian Cavity-Nesting Vegetation Birds • Introduced Mesquite outcompetes native riparian vegetation. • Red-vented Bulbul displaces native cavity-nesting birds. Disease & Biosecurity Protocols Imported Mycoplasma Released Biosecurity Falconry Stock Detection Houbara Measures 7 Quarantine & Mechanical Removal Pathogen Screening (Community Schemes) • Surveillance detected Mycoplasma in released houbara, traced to falconry stock. • New protocols include quarantine, screening, and piloted mesquite removal. Department of Environmental Sciences I Academic Year 2024-2025.

Mega-Projects & Wildlife Migration Challenges CONFLICT: Intersection of Development & Corridors NEOM Megaproject Houbara & Striped Hyaena Migratory Corridors SOLUTION: Science-Based Mitigation & Financing GIS-Based Least-Cost Path Analysis Recommends Optimal Routes Elevate Sections & Install Underpasses (Every 5 km) Recommends Optimal Routes Environmental Impact Bonds Riyadh Megaproject Contractor Payments Post-Construction Monitoring Outcomes Align Economic Incentives with Biodiversity Targets.

Technological & Collaborative Frontiers in Conservation Advanced Monitoring Genetic Barcoding Cryptic reptile taxa identification Remote Sensing & A1 Detection UAV-LiDAR Mapping micro-refugia A1 Acoustic Sensors Environmental DNA (eDNA) Non-invasive monitoring of desert springs Interdisciplinary Collaboration O Critical for co-producing scalable solutions • Engineers Social Scientists Real-time identification: gunshots & leopard calls Department of Environmental Sciences I Academic Year 2024-2025.

Strengthening Wildlife Protection: Regulations & Enforcement Updated Hunting Regulations Fines up to 100,000 SR for killing protected species Specific protection: Asir magpie Mandatory imprisonment for repeat offenders Technology-Driven Enforcement Special Forces for Environmental Security Integrate drones and ground patrols Achieving 70 violation detection increase Combatting Wildlife Trafficking Wildlife Crime Units collaborate with customs Intercept online trafficking Targeting illegal trade (e.g., lizards, falcons).

Protected Areas and Species Recovery in Saudi Arabia Strategies for Conservation and Governance Designated Reserves & Species Recovery Spatial Prioritization & Royal Reserves Endemism Hotspots Migratory Corridors Fencing & Protection Water Provisioning Grazing Exclusion Royal Reserves (10% Land Coverage) Traditional Land Tenure State Oversig 15 Reserves covering 4% of Kingdom. Enabling species population growth. 11 Department of Environmental Sciences Extending governance and integrating management approaches. IAcademic Year 2024-2025.

Arabian Oryx: A Conservation Success Story 1972: Last wild individual photographed. Long-term Political Commitment 1986: Captive herd founded from US zoos. 1990: First reintroduction to Mahazat as-Sayd. 2011: Wild population exceeds 1,000. Key Success Factors Habitat Restoration 8 Predator-Proof Fencing IUCN 2017: IUCN reclassifies as VULNERABLE. 00 CD Adaptive Harvest Quotas for Sustainable Tourism.

[Audio] Module 02 Causes of Extinction Analyzing the primary drivers of biodiversity loss.

[Audio] The Five Major Drivers of Biodiversity Loss Primary Causes of Extinction Habitat Loss Climate Change Overexploitation Primary Driver Accelerating Threat Direct Impact 70% of ice free land altered by humans. Deforestation, agriculture, and urbanization destroy critical habitats. Affects 15801 plus species on the I-U-C-N Red List. Only 1 degrees celsius rise has caused mass coral bleaching. Overfishing, bycatch, and illegal wildlife trade push species to extinction. Oceanic Whitetip shark: populations crashed 98%. Selective harvesting alters evolutionary trajectories (for example, tuskless elephants). Fragmentation isolates populations, reducing genetic diversity and gene flow. Arctic warming 4× faster, causing habitat loss for polar species. Invasive Species Pollution Biological Threat Environmental Degradation 25-50% of alien species successfully establish. They outcompete natives, spread diseases, and alter habitats. Pesticides, plastics, and chemicals contaminate ecosystems. Agricultural chemicals poison vultures and other scavengers. Ocean plastic pollution entangles marine life and enters the food chain as microplastics. Water hyacinth deoxygenates rivers, killing fish populations. Critical Finding: These drivers interact synergistically. Climate change exacerbates invasive species spread, habitat loss increases vulnerability to all other threats, creating feedback loops that accelerate biodiversity loss..

[Audio] Climate Change and Habitat Destruction Two Primary Threats Creating Destructive Feedback Loops Climate Change Habitat Destruction Temperature Rise Deforestation Global temperatures have risen ~1 degrees celsius, causing species to shift ranges. Arctic warming is 4× faster than global average. The Amazon rainforest is now a patchwork of fragments. 70% of land has been altered by humans, destroying critical habitats. Coral Bleaching Wetland Loss 14% of coral reefs lost in a decade. The Bramble Cay melomys was the first mammal to go extinct solely due to climate change. 85% of wetlands have disappeared since 1970, affecting water purification and flood control. Extreme Weather Fragmentation Events like Australia's 2019-2020 bushfires (killing 3 billion animals) are intensified by climate change. Roads and development isolate populations, creating barriers that reduce genetic diversity and prevent recolonization. Synergistic Effects: Climate change exacerbates habitat loss. Deforestation reduces carbon sequestration, accelerating warming in a destructive feedback loop..

Comparative Habitat Loss Across Major Biomes Analyzing differential responses to human pressures and highlights of severe losses. Tropical Rainforests High biodiversity, intense agriculture & logging. Rapid, often irreversible loss. Habitat Loss 500/0+ Severe losses in dry tropical forests. Temperate Forests Urbanization & forestry. Resilient, but historical fragmentation. Habitat Loss = 30-40%, regrowth Grasslands Agriculture & grazing. Highly vulnerable to conversion. Habitat Loss 40-50% Wetlands Drainage for development & agriculture. Critical, often overlooked systems. Habitat Loss Mediterranean Forests High human population, fire, & development. Critical threat. Special Focus: Severe Losses Dry Tropical Forests Often cleared for cattle & crops. Less attention, higher vulnerability. 600/0+ 60-70%.

Habitat Fragmentation: Effects & Dynamics Impact on Species and Ecological Processes FRAGMENTATION PROCESS REDUCED AREA REDUCED AREA INCREASED ISOLATION EDGE EFFECTS ORIGINAL HABITAT FRAGMENTATION SPECIES DECLINE & EXTINCTION RISK KEY CONCEPTS O Extinction Debt & Time Lags Delayed species loss after fragmentation; populations may persist briefly but face eventual extinction. Metapopulation Dynamics Interactions between separated populations; persistence depends on colonization balancing local extinction. Edge Effects Alterations in microclimate, resources, and species interactions at the boundary of habitat fragments. Conservation Biology for All: A University Course I Module 3: Threats to Biodiversity.

Overexploitation & Species Decline Understanding Threats, Cascading Effects, and Synergies Threats to Survival Overhunting: Removal of individuals at unsustainable rates. Overfishing: Depletion of marine populations. Illegal Trade: Unregulated commerce in wildlife and products. Cascading Ecological Effects Keystone Species Loss: Disruption of trophic structures and ecosystem services. Ecosystem Imbalance: Altered community composition and reduced resilience. Interaction with Habitat Loss Habitat Loss Overexploitation Synergistic Impact: Combined threats accelerate population declines. Accelerated Extinction Risk Module: Threats to Biodiversity I Course: Conservation Biology for All I [Semester/Year].

Overexploitation: Bushmeat & Overfishing Bushmeat Hunting in Tropical Forests Disrupted Food Webs Overfishing in Marine Ecosystems Collapsed Fish Stocks Impacts • Ecosystem Instability • Loss of Biodiversity • Threats to Livelihoods Solutions • Sustainable Management • Enforcement of Regulations Impacts • Food Web Disruption • Economic Loss • Community Vulnerability Solutions • Marine Protected Areas Quota Systems Effective Monitoring.

Understanding Invasive Species: Mechanisms, Examples, and Challenges Defining the threat and its multifaceted impacts on global ecosystems. 1. Definition & Mechanisms O Outcompeting Natives Altering Habitats Spreading Disease 2. Ecosystem Examples Islands: e.g., Brown Tree Snake (Guam) Rapid species loss due to lack of predators. Forests: e.g., Kudzu (SE USA) Smothers native vegetation, alters light. Aquatic Systems: e.g., Zebra Mussel (Great Lakes) Clogs infrastructure, disrupts food webs. 3. Key Concepts & Management O Lag Effects Time delay between introduction and noticeable impact, complicating early detection. Management Challenges Complexity in control, high costs, policy gaps, and potential for unintended consequences..

[Audio] Module 03 Vulnerability & Consequences Understanding why some species are more vulnerable and the cascading effects of extinction.

[Audio] Factors Increasing Vulnerability to Extinction Why Some Species Face Higher Extinction Risk Narrow Geographic Range Specialized Requirements Small Population Size Species with restricted distributions are highly vulnerable. A single localized event can wipe out their entire population. Specialist species with narrow ecological niches cannot adapt to environmental changes or utilize alternative resources. Small populations lose genetic diversity rapidly through genetic drift, leading to inbreeding depression. Example: Many Amazon tree species exist in small, specific areas. Examples: Koalas (eucalyptus), Giant pandas (bamboo), many orchid species. Data: Populations <10 pairs have a 40% extinction probability over 80 years. Trophic Level Limited Dispersal Life History Traits Top predators are vulnerable due to small populations, slow reproduction, and dependence on prey availability. Low reproductive rates and long generation times limit recovery from disturbances. Species with limited ability to move cannot escape threats or colonize new suitable habitats. Examples: Elephants, whales, and large sharks are vulnerable due to slow reproduction. Examples: Flightless birds, corals, and many plant species cannot relocate. Examples: Tigers, polar bears, and lions face threats from multiple angles. Overhunting, overfishing, and illegal trade directly reduce populations and disrupt social structures. Human Exploitation The Allee effect can create a negative feedback loop where small populations become even smaller. The Four Ds Framework: Species face Destruction, Degradation, Decline, and finally Disappearance. Vulnerable species are more rapidly affected by each stage..

[Audio] Ecological Consequences of Extinction The Cascading Effects Throughout Ecosystems Loss of Ecosystem Services Disrupted Food Webs Extinction disrupts critical services like pollination, water purification, and climate regulation. The loss of one species can cause cascading effects throughout an ecosystem, leading to secondary extinctions. Example: Sea otter decline leads to urchin overgrazing, creating "urchin barrens" that destroy kelp forest ecosystems. $235B $10T Pollination/year Global impact/year Reduced Resilience Genetic Diversity Loss Extinction eliminates unique evolutionary histories and potential, reducing adaptability and losing valuable resources like medicines. Human Health & Livelihood Impacts Diverse ecosystems are more stable. Losing species reduces resilience to disturbances like droughts, floods, and disease outbreaks. Biodiversity loss directly affects human health through reduced food security, increased disease transmission, and loss of traditional medicines. It impacts livelihoods, especially in rural communities, and can increase political conflict. Consequence: The Green Revolution's genetic uniformity led to widespread crop vulnerability. Impact: Monocultures are vulnerable to disease, while diverse systems have backup species and functional redundancy..

[Audio] Gene Pool Erosion and Genetic Diversity Loss Case Study: Green Revolution Irreversible Loss of Evolutionary Potential The 1960's-70's Green Revolution used genetically uniform crops , creating vulnerability to disease and environmental change. Genetic Erosion in Small Populations Corn Rust Epidemic (1970) Inbreeding Genetic uniformity led to massive crop losses, revealing the dangers of reduced genetic diversity. The epidemic demonstrated how genetic uniformity creates vulnerability. Increases homozygosity, exposing deleterious mutations. Genetic Drift Random loss of alleles, reducing variation. Reduced Adaptability Less capacity to adapt to environmental change. Rate of Genetic Loss Ne = 10 Ne = 5 40% 65% Loss after 10 generations Loss after 10 generations Critical Impact: Genetic diversity loss is irreversible. It represents the permanent loss of evolutionary potential and adaptability, making species more vulnerable to all other threats..

[Audio] Loss of Ecosystem Services and Livelihoods A Human Crisis Threatening Life Support Systems Provisioning Services Regulating Services Biodiversity provides food, fresh water, timber, and medicine. Loss threatens these essential resources. Ecosystems regulate climate, purify water, control floods, and pollinate crops. Their loss has massive economic and social impacts. Food Security Pollination Wild relatives provide genetic material for crop improvement. Worth $235B/year; pollinator decline threatens 1/3 of global food. Medicines Wetlands ~25% of modern drugs come from rainforest plants. Affecting 2 billion people due to reduced water purification. Cultural & Social Services Biodiversity loss affects recreation, tourism, spiritual practices, and cultural identity, impacting mental well being and community cohesion. The Biodiversity Human Well being Connection: Biodiversity loss is a human crisis. It threatens the natural life support systems we depend on, affecting health, livelihoods, and global stability. The most vulnerable communities bear the greatest impacts..

Ecosystem Services: Benefits from Nature Provisioning Services Food, fresh water, wood, fiber, genetic resources. Regulating Services Climate regulation, flood control, disease regulation, water purification. Underpinned by Biodiversity Supporting Services Nutrient cycling, soil formation, primary production, photosynthesis. Cultural Services Aesthetic, spiritual, educational, recreational, tourism. Human Well-being (health, security) Degradation Affects O Economies (resources, jobs) Survival (food, clean water).